X-ray tube.



No. 805,795. PATENTED NOV. 28, 1905. J. O. HEINZE, JR.

X-RAY TUBE.

APPLICATION FILED MAR. 16. 1905.

JOHN OTTO HEINZE, JR, OF LOWELL, MASSACHUSETTS.

X-RAY TUBE.

Specification of Letters Patent.

Patented Nov. 28, 1905.

Application filed March 16 1905. Serial No. 250,398-

To all whom it may concern:

Be it known that I, JOHN OTTo H EINzE, Jr. a citizen of the United States, residing at Lowell, in the county of Middlesex and State of Massachusetts, have invented certain new and useful Improvements in X-Ray Tubes, of which the following is a specification.

My invention relates to X-ray tubes, and its object is to provide means whereby only so much of a body as the operator of the tube may desire may be subjected to the action of X-rays.

As is well known, X-rays radiate spherically from the point of bombardment on an anode, and hence subject all bodies in the sphere of activity of the X-rays to their action unless the objects are protected from said rays. In case the object is a living being the rays are likely, for example, to burn the flesh, neutralize the growth of spermatozoa, and,in fact, be a menace to those who often use X-rays, as in surgery or in laboratories. Obviously there is a great necessity so to confine the action of X-rays that neither the operator nor portions of a body not to be treated will be affected by them. Now by means of my invention X-rays may be so confined.

The figure shows an anode of a common X- ray tube provided with my invention in vertical section.

In the drawing illustrating the principle of my invention and the best mode now known to me of embodying that principle A is an X-ray tube, B its cathode, and D its anode, the novel feature of my invention. The anode D has a stem (Z of iron. Mounted on the free end of the stem is the confining-shield E, made of suchmaterial as will absorb X-rays, metals, as lead and bismuth, which have the greatest atomic weights, being most suitable. This shield E has two holes (Z d at an angle with each other,one, (Z, extending through the shield and being, say, at right angles to the axis of the anode-stem d, and the other, (Z, being in said axis and openinginto the first hole (Z. A

face or point of bombardment O, of hard metal, as platinum, is mounted, as by brazing, upon a metallic plug, which is screwed into a threaded arm of the hole d. The anode and cathode occupy their usual relations to each other.

In operation a cathode-stream (indicated in dotted lines 6 7)) freely enters the shield E through the hole d and bombards in the wellknown way the face C of the anode D, but plainly only those rays which do notimpinge against the sides of the holes (Z d within the shield E and are not absorbed by said shieldnamely, rays 0 ccan pass through the glass of the X-ray tube A and have any effect outside it, as upon a hand X, which has only a limited area Y subject to the action of these rays 0 0.

It will now be plain how the action of X- rays may be limited to a required area and that the openings, as (Z (Z, in the shield may as to their location, size, and shape be varied as desired to suit the purpose for which the X-rays are to be used.

Knowing that the principle of my invention may be embodied in difierent forms without departing from the spirit thereof, I desire to protect my invention in the broadest manner legally possible.

What I claim is In an X-ray tube, a cathode; a shield made out of metal, and mounted on the end portion of an anode-stem; said shield having two holes; the first hole passing through it, a portion of said hole having a thread cut therein; the second hole leading into the first hole to receive the cathode-stream; a plug having a hard metal surface, mounted on the end thereof, and being provided with a screw thread, whereby it may be screwed into the thread portion of said second hole, to secure the point of bombardment of the anode in the path of the cathode-stream.

In testimony whereof I affix my signature in presence of two witnesses.

JOHN OTTO HEINZE, JR.

\Vitnesses:

L. W. CUTTING, E. A. PERHAM. 

